Oil cooler



March 28, 1933.' w. R. RAMSAUR E1' AL OIL COOLER Filed Nov. 16, 1929 3 Sheets-SheerI 1 l www); @fiese March 28, 1933. w. R. RAMSAUR Er AL OIL COOLER Filed Nov. 1e, 1929 s'snee't's-snet 2 .March 28, 1933. 1,902,970

W. R. RAMSAUR ET AL oIL COOLER Filed Nov. 16, 1929 3 Sheets-Sheet 3 gwomkou 2);@ Zmf FC5/:Qin wie Patented Mar. 28, 1933 UNITED STATES PATENT OFFICE WALTER R. RAHSAUR, OF LOCKPORT, NEW YORK, AND THERON' P. CHASE, OF DETROIT,

MICHIGAN', ASSIGNOBS TO GENERAL MOTORSv RESEARCH CORPORATION, OF DE- TROIT, MICHIGAN, A CORPORATION F DELAWARE OIL COOLER Application led November 16, 1929. Serial No. 407,730.

It is an object of this invention to provide simple, reliable, inexpensive and eilic1ent cooling or heat-exchange units, suitable for use upon automotive vehicles, for the cooling of lubricating oil or the warmin thereof.

These units are intended to e especially suitable for use in an oil cooling system such as that disclosed in pending application 354,245, filed April 11, 1929,-in which a plurality of vwater pumps are employed; but they may be used, with like advantage, in systems employing a single water pump, as hereinafter referred to, or in systems in which an oil cooling water circuit is maintained entirely distinct from an engine cooling water circuit, or elsewhere. f

It is a special object of this invention to provide a cooler of the tubular'core type in which a stack or stacks of substantially straight and thin-walled tubes are so. disposed that numerous thin streams of oil, or the like, may be passed through between successive pairs of tubes, preferably in orderly staggered rows, in such manner as to be repeatedly subdivided by encountering cylindrical surfaces or angular edges of the tubes in the successive rows,-the result being a scrubbing action, interrupted by more or less of turbulent flow, which prevents the adhesion of insulating films to the mentioned tubes and assures effective transferof heat through the thin walls referred to. rlhe novel cooler may incidentally effect a iltering.

This invention aims to provide a relatively great number of thin but broad and staggered oil passages, some or all of which are defined by the walls of elements, such as circular or polygonal tubes, adapted to contribute to the structural rigidity of the entire assembly and to transfer heat to or from water, or the like, advanced through said tubes at a rate and temperature suitable to the desired thermal eect. The cross-sectional configuration of the mentioned tubes may vary and may provide for either comparatively small or comparatively large areas substantially normal to the general direction of oil flow. Either baflling or stream-lining effects, or both, may be obtained; and the oil pressure and consequentvelocity may be comparatively high, thereby contributing to the mentioned scrubbing action. The use of cylindrical tubes of a known type, with hexagonal or other enlarged ends, permits a high oil pressure without risk of collapse, but additional forms illustrated share therewith the merit that the two fluids respectively contact n with opposite surfaces of each wall.

This invention may further. involve the use of novel diffusion elements in the path of one or both of the mentioned fluids, to assure a comparatively uniform or other predetermined distribution of iiow throughout the assembly or unt; and the mentioned diffusing or flow-controlling elements are preferably so formed that their mere insertion,

during assembly, assuresan advantageous posltionmg of the sama-no separate securing means or measures being required.

' It is a further object of this inventionto employ, in combination with Vthe mentioned stacks or sets of straight and circular or polygonal tubes, a single pair of side plates. These are preferably so shaped as to contribute to the structural rigidity of the entire unit, and so spaced as to insure a desired flow past even the external walls of the outermost row of tubes inclosed thereby; and, to c0- operate with the mentioned side plates, preferred embodiments of this invention may include one or more pairs of novel headers,- adapted to receive the mentioned diffusion plates and optionally provided with corrugated edges which interlit with the mentioned corugated walls and/or with the ends of tu es.

Other objects of this invention may be best Figure 2B may be regarded either as a completion of Figure 2A or as a disclosure of similar unit employing dii'erent tubes, parts being cut away in an analogous manner. Figure 3A is a vertical sectional view taken substantially as suggested by the lines 3-3 of Figures 1 and 2, with partsvbroken awa Flgure 3B is a vertical sectional view which may be regardedl either as a completionof Figure 3A or as a disclosure of alternative features,-parts being cut away in an analogous manner.

Figure 4 is a double-scale side elevational view of a single core tube of one type suitable for use herein,-a core being formed by simply securing adjacent edges or abutting faces of the enlarged ends together.

`,Figure 5 is an end view, taken substantially as suggested by the arrow 5 of Figure 4. I

Figure 6 discloses, in addition to a sect1on which may be regarded as talen in the plane of the line 6-6 of Figure 4, a plurality of alternative cross-sectional outlines such as may be given to tubes, within the scope of the present invention, the Walls of said tubes being free from concave surfaces or re-entrant angles. Y

Figures'? to 9 are respectively diagrammatic elevational views of some. of the numerous systems to which the novel oil cooler herein described is suitable.

Referring first to features shown in Figures 1, 2A, 3A and 4, an oil cooler unit is shown as comprising, in addition to a stack or set or straight core tubes 10, and corrugated side walls 11, 11', a pair of oppositely concave water headers 12 and 12' (respectively formed from sheet metal and provided with an inlet tubulation 13, and an outlet tubulation 13'), and also with a pair of stamped headers 14 and 14',-respectively provided with threaded openings at l5 and 15'; but it will be recognized that both pairs of headers might be formed of cast metal, and that the l means employed to connect pipes therewith is relatively unimportant.

The respective core tubes 10r are shown in Figures 2A, 5 and 6 as circular in crosssectional outline, although provided with slightly enlarged hexagonal end portions 16, 16 adapted to be brought into lateral engagement with like end portions upon adjacent tubes, to produce the known honeycomb effect best shown in Figure 2A,-the differ-` ence between the outside diameter of the circular portion of each tube and the minimum outside diameter of the hexagonal end portions thereof being. such as to provide a desired small clearance, compelling the oil to be cooled (or heated) to advance in thin streams therebetween.

Itwill be understood that, upon suitably assembling the requisite number of tubes the enlarged ends of a set thereof may be soldered together by momentary immersion, or united by an equlvalent operation; and, to permit the passage of oil not only between the adjacent pairs of tubes but externally of the outermost rows thereof, the walls 11, 11' may be so corrugated, when this effect is desired, as to maintain a substantially uniform distance from the adjacent tubes,-this distance being substantially the same as that between the respective pairs of tubes. In other words, in case the tubes are circular in cross-section, the inner surfaces of the mentioned corrugations may also be circular in cross-sectional outline and of substantially the same external radius, or they ma be such as to produce any desired ratio of db or othervwall and adjacent tubes.

The respective water header elements 12 and 12 may be so formed as to be interchangeable, each bein provided with a concavity 17 of suflcient epth to adapt the same to function as a manifold, and rovided also with a peripheral flange 18; t e mentioned concavity may be adapted to receive a waterditfusion plate 19, having inwardly or oppositely bent edge ortions 20, 20', adapted to establish its positlon within the concavity 17, spacing said plate away from the ends of tubes 10; and the flange 18 may be provided, along its lon er edges, with corrugations 21, adapted to lntertit with any corrugations provided by or in the walls V11, 11'. The plate 19 is shown as provided with spaced openings 22; and these, whether uniform or varying in size (to eiectl a desired distribution of flow), may be so positioned that each open ing substantially coincides with a point of junction of three of the hexagonal end portions of the mentioned tubes 10.

The respective oil headers 14, 14' may advantageously be so cast or shaped that upper w between a corrugated and lower flanges 23, 23 thereof shall intert with the hexagonal or other enlarged ends of aterminal row of tubes 10, and shall also intert in interlocking relationship beneath the mentioned flanges 18 upon the water headers 12, 12'; and, if desired, the oil inlet header 14 may receive a diffusion plate 24, provided with openings 26. Whether uniform or nonuniform in distribution and size, these openings correspond in function to those of the mentioned diffuser plate 19.

Although satisfactory results have been obtained by the 'use of tubes and corrugated side plates of exactly the described types, and although substantially -uniform and equally spaced openings may be used in the mentioned diil'user plates, (a marginal row of small openings being suggested at 19', Figure 2A) Figures 2B and 3B respectively suggest the use of plates containing openings which are graduated in size and/or distribution,the more central openings 261i in the plate 19?; being smaller than the relatively remote openings 266', in order that the flow of water through the remote tubes may be substantia-lly equal to or even greater' than that through the centrally dis osed tubes. Similarly, Figure 3B, the p ate 251; is shown as provlded with comparatlvely small openings 27 b, 'near the middle thereof, and with comparatively large openings 27 b near the edges and corners thereof.

As sug ested in Figure 6, a considerable number o? alternative cross-sectional outlines may be given to core tubes employed -in the described manner, a substantially square outline being suggested at a, a diamond-shaped outline at 10b, a lenticular outline at 10o, an elliptical outline at 10d, and ovoidal outline at 10e optionally providing an edge at e,-no end con guration being shown. Any of these outlines may be provi ed with hexagonal or other laterally-abutting end portions of a suitable type; but it is found advantageous to keep the space between tubes down to ,1g inch or less.

Obviously the exact style of corrugation of the reinforcing and How-controlling side walls 1l, 11 may depend upon the crosssectional configuration of the tubes contacting therewith or spaced therefrom; and the latter need not ordinarily be graduated or varied in style or size as suggested in Figures 2A. and 2B. Even if the central parts of the tubes are adapted slightly to collapse laterally, in consequence of changes in the pressure or in the viscosity of the oil, the end portions of a given set of tubes may all L alike be hexagonal or square or diamond shaped,-the interiitting parts of the oil headers and the side lplates being of corresponding configuration. Extruded tubes with hexagonal ends have been found entirely satisfactory; and it will be noted that, in case ovoidal forms 10e are used, the successive rows thereof may alternate as to the direction in which the comparatively sharp edges 'of such tubes are disposed,-as suggested near the center of Figure 2A, at e It will be recognized as highly advantageous that, in these oil cooling and heat-exchange units, no wall elements are required .additionally to the two mentioned side plates,

preferably corrugated and interfitting with some or all of the mentioned headers; that, soldering being deemed preferable to any use of gaskets herein, the ends of the terminal rows of tubes may be secured to iianges of the adjacent oil headers, and/or the endsl of side rows of tubes may be secured to adjacent side plates (said plates and said headers being preferably about equal in length to said tubes) by the same partial-immerslon soldering operation by which an entire set of hexagonal or other enlarged ends is integrally unied.

The ends of the side plates being preferably receivable within flanges of the oil headapertured brackets 30, for the support of the unit. Corrugation of the plate-engaging orlions of t e flanges 18 obviates necessity -or providing flat edge 4portions upon the corrugated side plates,-which can accordingl be cut from uniform sheet or strip stoc the headers of each pair ma be ident1.

cal in form, that header (if either) into which a distributing plate is insertedin ad- Vance of the soldering thereof in place being thereby qualified to serve as an intake; and any desired uniform or non-uniform flow may be provided for bythe use of special sizes, shapes and/or distribution of holes in the diffusion plates 19 and 24,-preferably provided with integral positioning means. For example, to offset an inflow of heat from some hot environment, the distribution holes near the periphery of plate 19, in the water inlet header, may be enlarged beyond a size requisite to equality of low.

The term water is herein applied generally to a relatively thin heating or cooling fluid, and the termy oil is intended to include any relatively thick or viscous fluid to be heated or cooled. It is found best to advance the latter externally of the tubes, in order to obtain the scrubbing effect due to the use of very thin passages therebetween; but the water headers obviouslymay be entirely omitted when the unit is to be merely immersed as in a cold stream or bath of brine or the like.

Units of the described form admit of the easy application of any desired external insulation and/or reinforcement not shown; the described cross-sectional outlines adapt the tubes to withstand, if necessary, high and/or unequal pressures and e'ect to some extent automatic equalization of flow spaces between the tubes of the transverse rows,- lateral pressure being diminished with increase of -velocity of How; and a slight lateral collapse of the non-circular forms, varying the extent of the scrubbed surfaces provided thereby, may automatically increase the clearance therebetween with increased oil pressure,-the extent of such collapse being variable, in turn, by varying the pressure upon the cooling water.

It is ,believed that diagrammatic Figures 7 ,and 8 will be suiiicientlyexplained by the. legends thereon,-any oil cooler within the scope of the present invention being suitable for use as suggested at 29, Figure 7 or as suggested at 29', Figure 8, or in any analolgous system. Valve 30 in pipe 31, Figure 7,

may so open at a predetermined pressure as to by-pass cooler 29 and it may open, at a higher pressure, a return connection 32 to pan 33 and this organization will be seen to be somewhat simpler than that shown in Figure 8,-requiring two oil pumps 34 and 35 and one water pump 36 ;but the inclusion of a filter 37 in either circuit 38 or circuit 39 should be regarded as entirely" optional, ineither or any system.

In case the cooler unit is desired to serve also---as a filter unit, a valved pressure pipe 40 may be connected with its outlet manifold, and a valved drain pipe 41 may be connect ed wlth its inlet manifold, as suggested in f Figure 7, any desired pressure means and,` any desired valve-operating means being used therewith.

Shutters 42 and/or a by-pass 43 may be so provided as to obviate any undue cooling or to facilitate warming of oil, and may be manipulated by suitable manual means and/or by automatic means. For example a thermostat-44 may render the closing of shutters 42 and/ or the opening of by-pass 43 dependent upon the temperature of the cooling water leaving the engine jacket,by a pull upon a link 45 and/or a link 4,6. The latter is shown as pivotally connected with an arm 47 of a valve 48. Alternatively or additionally a thermostat 49, responsive to the temperature of the oil that has been acted upon by the cooler and/or has entered the engine proper may manipulate said shutter and/or said valve; as by means of thrusts applied through rods 50 and/or 51 (optionally containing springs, not shown) Figure 9 suggests the use of an oil heater 29a distinct from an oil cooler 296,-any required pumps being used on either side there,- of. The flow of heating and/or cooling iuids and/or oil from a pump 34a may, in this instance, be varied by means such as an exitoil thermostat 49a. For a heating effect, water may be shunted from the engine jacket, as by way of a pipe 48a, or direct or indirect use may be made of heat from an exhaust pipe 52a. For example, a heating fluid may enter and exit through tubulations 13a and 13a; but it will be understood that the heat exchange elements 29a and 29a need not be so separate as Fig. 9 might seem to imply.

Although the foregoing description has included details of but one complete embodiment of this invention, optional features being incidentally suggested, it should be understood not only that various features of this invention might be employed, but also that numerous additional modifications might easily be devised, by workers advised of the foregoing,-all without the slightest departure of the scope of the present invention.

We claim:

1. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; anda pair of oil hea ers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers, to pass in streamswhose thinness is determined by the cross-sectional configuration and spacing of said tubes.

2. In a ltubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers,'to pass in streams whose thinness is determined by the cross-sectional configuration and spacing of said tubes,-,said headers being substantially identical in form.

3. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional configuration and spacing of said tubes,-said headers being substantially identical in form and shaped to fit over said 'end portions of said side plates.

4. In a tubular-core oil cooler: a set of parallel tubes arranged -in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging" end rows of said tubes and end portions of said plates as to compel oil advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional con- `figuration and spacing of said tubes, said headers being substantially identical in form and shaped to receive a diffusion plate interfitting therein.

5. In a tubular-core oil cooler: a set of parallel tubes'arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional configuration and spacing ofsaid tubes,-one of said headers containing means for predetermining a diffusion of fiow past said tubes.

6. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional configuration and spacing of said tubes,-a dimension of said plates and a corresponding dimension of said headers being substantially the same as the length of said tubes.

7. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging-end portions of said tubes; and a pair of oil headers so engaging endrows of said tubesand end portions of said plates as to compel oil, advancing between said headers, to ass in streams whose thinness is determined y the cross-sectional configuration and spacing 'of said tubes,- said plates being'provided with corrugations vextendingsubstantially parallel with said tubes.

l8. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows of said tubes and end portions of said plates as to compel oil, advancing between said headers, to ass in streams whose thinness is determined y the cross-sectional configuration and spacing of said tubes,-

rows of saidtubes and end portions'of said plates as to compel oil, advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional configuration and spacing of said tubes,-said plates being provided with corrugations so spaced from said tubes, in an intermedlate region thereof, as to permit oil to pass externally of said tubes.

10. In a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging end ortions of s ald tubes; and a pair of oil hea ers so engaging Ven d rows of said tubes and end portions of said plates as to compel oil, advancing be'- tween said headers, to pass in streams whosev thinness is determined by the cross-sectional configuration and spacing of said tubes,-

only the ends of side rows of said tubes being secured to said plates. f

11. ln a tubular-core oil cooler: a set of parallel tubes arranged in rows; a pair of side plates engaging, end portions of said tubes; and a. pair of oil headers so engaging end rows of said tubes and end portions o said plates as to compel oil, advancing between said headers, toppass in streams whose thinness is determined by the cross-sectional coniguration and spacing of said tubes,-some of said tubes having rounded surfaces upon flow-receiving sides thereof.

12. ln atubular-core oil cooler: a set oi parallel tubes arranged in rows; a pair of side plates engaging end portions of said tubes; and a pair of oil headers so engaging end rows ofsaid tubes and end portions of said plates as to compel oil, advancing between said headers, to pass in streams whose thinness is determined by the cross-sectional I configuration and Vsplacing of said tubes,A aving edges upon'thesome of said tubes How-receiving sides thereo 13. In a tubular-core oil cooler: a set o f parallel tubes; a pair of side plates -engagin end portions of some of said tubes; a pair o oil headers engaging end portions of some of said tubes and end portions of said plates,

to compel oil, advancing between said head.

ers, to pass between said tubes in thin streams,

tor a scrubbing eect; and apair of water headers intertting with said side plates.

14. In a tubular-core oil cooler: a set of parallel tubes a. pair of side plates enga gl' end portions df some of said tubes; a audf oil headers engagin end portions o some of sald tubes and en ortions of said plates, to compel oil, advancing between said headers, to ass between said tubes in thin streams,

for a scrubbing eect; and a pair of water headers intertting with said side plates,- said water headers being provided wlth anges which extend over said side plates.

15. In a tubular-core oil cooler: a set of..

ers, to ass etween said tubes in thin streams,

for a scrubbing edect; and a pair of'water headers interitting with said side plates,- said water headers being provided with anges which extend over said side platesand over portions of said oil headers.

16. En a tubular-core oil cooler: a set of parallel tubes; a pair of side plates engagin end portions of some of said tubes; a pair o oil headers engaging end portions of some of said tubes and end portions of said plates, to compel oil, advancing between said headers, to pass between said tubes in thin streams, for a scrubbing eiect; and a pair of water headers interfitting with said side plates,- said side plates being corrugated and said water hea ers being provided with iianges interitting therewith.

' 17 ln a tubular-'core oil cooler: a set of substantially parallel tubes; a, pair of side plate elements; a pair of oil header elements; and a pair of water header elements,-one of said pairs of elements being provided with means to retain the mentioned parts in assembled relationship.

18. A tubular-core oil cooler of the character described in claim 17, in which said plate elements are so corrugated as to predetermine a iow of oil in thin streams past surfaces of said tubes, and in which the lastmentioned pair of header elementsis provided with iianges adapted to intertit with corru ations in said plate elements.

19. n an oil cooler: headers; flow passage elements adapting the same to function advancing between said head as a filter; and means, connected with said headers, to effect a reversal of `flow therein, for a clearing effect.

20. A11 oil temperature regulator which includes heat exchanging elements -between which there are provided spaces'in the neighborhood of y or less in width through which oil is adapted to How.

21. An oil temperature regulator which includes a plurality of parallel tubes through which a heating and/or cooling medium is adapted to How, and between which there are provided spaces fg or less in width through which oil is adapted to flow.

15 22. In an oil cooler, a plurality of parallel tubes on which there are provided enlarged ends which are united to form a core, plates united to the enlarged ends of the outer side tubes to form side Walls of the cooler, and

headers united to the sides of the plates and inclosing the outer end rows of the tubes.

23. In an oil cooler, a plurality of parallel tubes on which there are provided enlarged ends which are united to form a core, plates united to the enlarged ends of the outer side tubes to form side Walls of the cooler, headers united to the sides of the plates and inclosing the outer end rows of tubes, and headers secured to the ends of the plates and the ends of the first-mentioned headers and inclosing the ends of the tubes.

24. In an oil temperature regulator, a plurality of parallel tubes which are spaced apart for a portion of their length to provide oil passages andplates which form walls of the regulator and in which there are provided corrugations which are so arranged as to permit between the plates and the adjacent tubes a flow of oil comparable to that be- 40 tween the adjacent tubes.

In testimony whereof we atix our signa-v tures.

WALTER R. RAMSAUR. TRON lP'.' CHASE. 

